We were in the city last night for the comedy festival show Black Bag (review to follow), and so were able to enjoy Earth Hour from ground zero, as it were.
We saw the lights on the Arts Centre spire go out. We saw the lights dim at Federation Square and along St Kilda Rd.
It may be small thing, but standing and watching it happen around us was undeniably powerful.
Over the next few days we'll hear a lot of commentators talk about Earth Hour being "merely" a symbol.
And like ratifying the Kyoto Protocol and saying sorry to the stolen generations, it is a symbol. But symbols matter. Symbols are important. Symbols unite us and provoke us and focus our thoughts.
Andrew Bolt will drag out figures showing that the amount of energy saved was so minute that it clearly wasn't worth the effort. But this is to miss the point entirely.
Earth Hour is not about the level of emission reduction in that single hour. Symbols don't need to achieve anything measurable in themselves. That's not what they're for. Symbols like this work to prompt change in other areas.
Earth Hour is about drawing attention to the problem of climate change. It's about the emissions reduced over the coming weeks, months and years as people come to understand that it's just not that hard to turn off the lights.
We're going to see a lot of change over the next few years. Changes in the weather, changes in our cities, and changes in society as the centres of power and money are shifted.
A symbol like Earth Hour, with its visual and visceral impact, will keep us focused our goals and reminded of the endgame. And that's very important.